While general online sentiment strongly favored President Barack Obama's statement, judgments of its political impact were much more closely divided.

By M. Alex Johnson, msnbc.com

Online reaction to President Barack Obama's endorsement of same-sex marriage is running 3-to-1 in his favor, but commenters are sharply divided over whether it will help him or hurt him in November, according to a computer-assisted analysis of hundreds of thousands of social media posts in the first 24 hours after the announcement.

The analysis examined 532,000 posts on Twitter and Facebook, about 300,000 of which expressed a clear opinion about Obama's statement. Of those, 72 percent approved of the announcement.

(The analysis — which ran from 3 p.m. ET Wednesday, when ABC News broadcast its interview with Obama, through 3 p.m. ET Thursday — used a tool called ForSight, a natural-language data platform developed by Crimson Hexagon Inc. For this type of sentiment analysis, Crimson Hexagon reports a margin of sampling error of plus or minus 3 percentage points among the self-selected social media audience. Click here for a detailed explanation.)

While Obama won widespread praise online, a significant proportion of it was grudging.

Many supporters of same-sex marriage criticized the president for not having announced his position until now, 3½ years into his presidency. Fully a third of those agreeing with the decision did so while asking, in essence, "What took you so long?"

Twitter.com

Twitter.com

A further 18 percent of those agreeing with the announcement complained that the president hadn't gone far enough, with some noting that he stopped short of taking any concrete action, such as proposing legislation or issuing an executive order to have federal agencies recognize same-sex marriages.

Twitter.com

Twitter.com

By contrast, opponents of Obama's announcement strongly indicated that they believed it was a politically cynical move.Nearly half of those opposing the move — 47 percent — expressed sentiments like these:

Facebook.com

Twitter.com

Interestingly, about a fifth of the sample — well more than 100,000 people — chose to analyze the announcement not so much on its merits but on whom it would benefit in the general election. And by 52 percent to 48 percent, a slim majority of those thought it would likely help Obama and other Democrats.

Twitter.com

Twitter.com

The social media analysis is also notable for its variance from public opinion at large. Recent polls generally indicate that only about half of Americans believe same-sex marriages should be legal; the most recent Gallup Poll, taken May 3-6, for example, showed a 50 percent to 48 percent split.

A possible explanation lies in the makeup of the social media audience.

The Pew Internet & American Life Project, which uses ForSight in its statistical analysis of social media, reported in March that people who identify themselves as liberal are more likely to use social networking sites than are people who identify as conservatives.